Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang, 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou, Zhejiang, 310058, China.
Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang, 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou, Zhejiang, 310058, China.
Environ Pollut. 2019 May;248:823-833. doi: 10.1016/j.envpol.2019.02.072. Epub 2019 Feb 27.
For the soil-plant ecosystem, knowledge about the effects of biochars on the soil silicon (Si) cycle is still tenuous. In this study, the effect of biochars on the yield, Si uptake and Si distribution within different tissues of rice plants and the soil Si cycles in a soil-plant system were investigated. Si-rich (RH300-700) and Si-deficient (WB300-700) biochars prepared from rice husk and wood sawdust were applied to high-Si soil (HSS) and low-Si soil (LSS). Biochar addition increased the yield of grain and straw and had no effect on the yield of root, and the increase in the yield with Si-rich biochars was obvious; this effect had a high response to LSS. Si-rich biochars increased the plant Si content of grain and root and had no effect on straw. RH300 amendment increased the Si concentration in grains, compared to RH500 and RH700. The addition of Si-deficient biochar to HSS had little effect on the Si content, while Si-deficient biochar-amended LSS had a great impact on the reduced Si content in rice straw and root, and WB700 decreased the Si concentration in grains, compared to WB300 and WB500. Finally, the Si-rich biochars increased the total Si uptake within rice, while Si-deficient biochars decreased the total Si uptake in LSS. According to the FTIR and SEM-EDX spectra of biochars before and after rice harvest, a new band of SiOSi at 471 cm was found after aged WB700, and the minerals of iron and Si were found on the surface of aged WB700; biochars can fix the dissolved Si on its surface as a temporary store to prevent Si loss. Therefore, biochars can be considered reservoirs of soil Si, which is a slow release source of available Si, to impact the speed of biogeochemical cycling of soil Si in agricultural paddy soil.
对于土壤-植物生态系统，生物炭对土壤硅（Si）循环影响的知识仍然很薄弱。本研究主要调查了生物炭对水稻植株的产量、Si 吸收和 Si 在不同组织中的分布以及土壤-植物系统中 Si 循环的影响。从稻壳和木屑中制备了富硅（RH300-700）和缺硅（WB300-700）生物炭，并将其添加到高硅土壤（HSS）和低硅土壤（LSS）中。生物炭的添加增加了籽粒和秸秆的产量，对根的产量没有影响，富硅生物炭的增产效果明显；这种效果对低硅土壤（LSS）的响应很高。富硅生物炭增加了籽粒和根的植物 Si 含量，对秸秆没有影响。与 RH500 和 RH700 相比，RH300 的添加增加了稻谷的 Si 浓度。在 HSS 中添加缺硅生物炭对 Si 含量影响不大，而在缺硅生物炭添加的低硅土壤（LSS）中，对水稻秸秆和根中 Si 含量的降低影响很大，WB700 与 WB300 和 WB500 相比，降低了稻谷的 Si 浓度。最后，富硅生物炭增加了水稻体内的总 Si 吸收量，而缺硅生物炭降低了低硅土壤（LSS）中的总 Si 吸收量。根据收获水稻前后生物炭的傅里叶变换红外光谱（FTIR）和扫描电子显微镜-能谱（SEM-EDX）图谱，发现老化的 WB700 后在 471cm 处出现了新的 SiOSi 带，并且在老化的 WB700 表面发现了铁和 Si 矿物；生物炭可以将其表面上的溶解 Si 固定为临时储存库，以防止 Si 损失。因此，生物炭可以被认为是土壤 Si 的储库，是农业稻田土壤 Si 生物地球化学循环速度的可用 Si 缓慢释放源。
